Full hole deflection tool



July 3, 1962 D. MCLEAN DUNCAN FULL HOLE DEFLECTION TOOL 3 Sheets-Sheet 1 Filed June 10, 1957 INVENTOR, 041v McLEA/V DUNCAN.

l/za/my July 3, 1962 D. M LEAN DUNCAN FULL HOLE DEFLECTION TOOL 3 F. UH L 4 f- M N w m Filed June 10, 1957 July 3, 1962 D. M LEAN DUNCAN FULL HOLE DEFLECTION TOOL 3 Sheets-Sheet 3 Filed June 10, 1957 w 4 M W E H d 4 M N I m w 3,042,125 FULL HOLE DEFLECTION TOOL Dan McLean Duncan, Los Angeles, Calif. Filed June 10, 1957, Ser. No. 664,588 21 Claims. (Cl. 175-73) This invention relates generally to method and apparatus for drilling bore holes in the earth and relates more particularly to such method and apparatus for controlling the direction of a drilling bit such as is used in the rotary drilling of said bore holes, as, for example, in the pro duction of oil well how holes or the like.

While the present invention has particular utility in the drilling of wells for the recovery of oil, and is shown and described in such connection, it is to be understood, of course, that its utility is not confined thereto.

In the drilling of wells by the rotary method, a drill bit is rotated by means of a string of pipe known as the drill string or stem, and as the bit penetrates the earth, additional sections of pipe are added. Such drill strings become very long and have considerable inherent flexibility.

Controlled directional drilling of oil wells has become .increasingly important. There are many situations Where the oil bearing formations are horizontally spaced a substantial distance from the point of initiation of the well bore, as for example, where such oil bearing formations are off shore and under water. The well may be initiated on shore or a number of wells may be drilled from an artificial island or the like and said wells fan out in the earth in diflerent directions. There are, of course, other situations where controlled directional drilling must he resorted to or comprises the best drilling procedure.

Various methods and apparatus have been proposed for controlling the direction and angle of deflection of the drilling hit and hence the Well bore. For example, directional whipstocks are used but various well known difliculties are encountered in using such devices.

In the drilling of wells to reach an oil bearing formation that is horizontally spaced from the point where the well is to be initiated, it is desirable to drill the bore on a large radius and it is an object of the present invention to provide a method and apparatus for controlled directional drilling by means of the conventional rotary drilling technique on such a large radius.

It is another object of the invention to provide apparatus connectible into the drill string and adapted to effect drilling of a curved deflecting bore of large radius without the use of other elements or instrumentalities than those incorporated into the drill string.

A further object of the invention is to provide method and apparatus for drilling a deflected hole on a true smooth are.

A still further object of the invention is to provide method and apparatus of this character whereby a very substantial amount of full gauge deflected hole may be made on the initial run.

Another object of the invention is to provide method and apparatus of this character whereby the same orientation of the various elements may be maintained.

Still another object of the invention is to provide method and apparatus of this character whereby the rate of deflection is variable by varying the pump pressure.

A still further object of the invention is to provide method and apparatus of this character whereby positive control of the amplitude of the radial movement of the deflecting device resides in the deflecting tool itself.

Still another object of the invention is to provide apparatus of this character wherein the cross sectional size of the deflecting tool is at a minimum when running in States Patent 6 ice or pulling out of a hole so as to ofler no obstruction to such operations.

A further object of the invention is to provide apparatus of this character wherein the deflecting tool. may be locked or unlocked at will.

A still further object of the invention is to provide appar-atus of this character which also may be used as a straight hole stabilizer.

By the expression curved bores of large radii as employed in this application, it is intended to identify and define degrees of curvature obtainable through the inherent flexibility of a normal rotary drill string. Generally speaking, the radii of deflecting bores, in the drilling of which the present invention is addressed, lie within the limits of 1,000 to 3,000 feet although not necessarily confined thereto.

A further object of the invention is to provide apparatus of this character that is relatively simple in design, simple and reliable in operation, and which may he readily disassembled for inspection and/ or servicing and readily assembled.

The characteristics and advantages of the invention are further sufficiently referred to in connection with the following detailed description of the accompanying drawings which represent certain embodiments. After considering these examples, skilled persons will understand that variations may be made without departing from the principles disclosed, and any structures, arrangements or modes of operation that are properly within the scopeof the appended claims are contemplated.

Referring to the drawings:

FIG. 1 diagrammatically illustrates a well, drilled in accordance with the present method and with the present apparatus;

FIG. 2 is a side view of apparatus embodying one ar-' rangement of the present invention;

FIG. 3 isa similar view showing an alternative arrangement;

FIG. 4 is a similar view showing still another alternative arrangement;

FIG. 5 is a longitudinal section of the deflection tool in the release position;

FIG. 6 is a similar view showing the apparatus in the well bore engaging position;

FIG. 7 is a sectional view taken on line 77 of FIG. 5;

FIG. 8 is a sectional view taken on line 8--8 of FIG. 6;

FIG. 9 is a sectional view taken on line 9-9 of FIG. 5;

FIG. 10 is a sectional View taken on line 10-10 of FIG. 5; and l FIG. 11 is a view similar to FIG. 10 showing an alternative arrangement.

Referring more particularly to FIG. 1, there is shown a well bore, indicated generally at 15' in the earth by means of the rotary method wherein a rotary drill 16 of any known type and is located at the lower end of a drill string which includes pipes 17 having collars 18. Behind the drill 16 is a deflection tool, indicated generally at 20, embodying the present invention, said tool 20 being connected to the drill, by means: of a sub 21. At the upper end of the deflection tool 20 there is a sub 22 to the upper end of which is connected collar 23. At the upper end of collar 23 is a second deflection tool, indicated generally at 24 to the upper end of which is secured a sub 25 to which is connected the adjacent end of the lower-most drill pipe 17 of the pipe string. As shown in FIG. 1, the bore 15 curves at 26 with the drill 16 aimed at the oil bearing formation or target 28.

The body of the deflection tool, FIGS. 5 to 10 in elusive, comprises a central tubular portion 30 and en- 3 larged diameter end portions 31 and 32, there being an axial bore 33 through said body. The end portion 31 18 provided with a tapered tapped bore 34 for reception of the usual externally threaded pin 35 of the adjacent part of the string. End portion 32 is provided with such a tapered externally threaded pin 36 for connection to the adjacent portion of said string.

On the central portion 30 there is a tubular body 40 of resilient, elastic material such as rubber, for example, said material being such as to resist any action by fluids to which same may be subjected. At the ends of the body 40 are collars -41 and 42, said body 40 and collars 41 and 42 operably filling the space between the end portions 31 and 32.

The body 40 is provided with an internal, annular groove 44 adjacent the longitudinal center thereof, said groove being connected by a lateral bore 45 with the longitudinal passage 33 whereby pressure in said passag 33 may be transmitted to said groove 44. A plurality of longitudinally extending runners or gripping elements 47 are embedded in the body 40 and are annularly spaced apart. At the respective ends of said elements 47 are pins 48 which extend longitudinally outwardly of the respective runners or elements 47 and also extend outwardly of the respective ends of the body 48. Outer edge portion 50 of the gripping elements 47 extends radially outwardly of the outer surface 51 of the body 40. The width of the gripping elements 47 is greater than the thickness of the body 40 so that the inner edge portion 52 of said elements 47 extend radially inwardly of the inner surface 53 of said body 40. Each of the gripping elements '47 is provided with a plurality of openings 54 therethrough, said openings 54 being filled with the material, as at 55, of the body 40 so as to thereby securely anchor the gripping elements 47 in said body. Along the side edge portions 50 and 52 the material of the body extends somewhat outwardly of the surfaces 51 and 53 respectively to converge against said edge portions 50 and 52. As best shown in FIGS. 7 and 8 the gripping elements 47 are thicker at the center thereof and taper toward the side edges so as to more securely anchor said elements in said body 40.

Collar 41 is provided with an internal annular recess in'which is operably received bearings and 61. These bearings may be of any suitable type such as, for example, roller bearings. Adjacent the outer end of bearing 61 there is a recess 62 in which is operably disposed a bearing 63 which is also shown as a ball bearing although any other suitable type of bearing may be used. At the outer lower corner, the collar 41 is provided with a recess 64 l for reception of a seal 65 of any suitable character. A similar seal 66 is disposed in a recess 67 at the upper inner edge of the collar 41. i As may be seen in FIGS. 5 and 6, the seals 66, the ends of the tubular body 40 in contact with the collars, and the longitudinal portion of the body 40 sealingly or substantially sealingly enclose the central portion 30 between the collars 41 and 42. The upper end of the collar 41 is provided with a plurality of annularly spaced recesses 68 of varying radial extent. At one angular position there is a short recess, indicated at 68a and diametrically opposite said recess 68a is the longest recess 6827. From the recess 680 the recesses increase in length progressively to the recess 68b and the adjacent pins 48 of the gripping elements 47 are operably received in the respective recesses.

The collar 42 is similar to the collar 41, there also being recesses 68 but said recesses are in the lower end of said collar facing the adjacent end of collar 41. The recesses 68, 68a and 68b in the collar 42 correspond to therespective recesses in the collar 41 in length and operably receive respective pins 48 of the adjacent ends of the elements 47. When pump pressure is applied to the resilient element 40 it will expand to complete circumferential contact with the well bore. However, the pins 48 are allowed only limited travel in the shorter slots with a minimum travel in slot 68a, FIG. 10, and progressively more travel in the other slots up to maximum travel in slot 68b. The action, therefore, is such that when the resilient element 46) expands into contact with the well bore and there is minimum travel at 68a and maximum travel at 68b, the central tubular portion 3! is forced olf-center as shown in FIG. 8. More particularly, the pin 48 in slot 68a contacts the outer end of said slot and forces the central tubular portion 34) off-center relative to the center of the well bore. As the pump pressure is increased, the force tending to move the central tubular portion off center is increased so that the force tending to deflect the hole is correspondingly increased as the pump pressure is increased. 7

The end of collar 42 opposite the end having the recesses 68 is provided with a plurality of annularly spaced longitudinally extending recesses 75, said recesses 75 being closely arranged, as best shown in FIG. 9. Recesses 75 are adapted to receive the adjacent end of a latching or locking pin 76 which has a tapered lower end 77. Intermediate the ends of said pin is a piston 78 of substantially greater diameter than pin 76 and which may be formed integrally with the pin or may be secured thereto by any suitable well known means. Piston 78 has an annular external groove thereabout for reception of a sealing ring or the like 79, said piston being operably disposed in a cylinder 80 in the end portion 32 of the body of the device. Cylinder 80 is located adjacent the periphery of portion 32 and extends longitudinally of the device. The lower end of the cylinder 80 is closed by an end wall through which extends a bore in which is snugly but operably received the adjacent portion of the pin 76, there being a seal 81 to provide sealing means about the portion of the pin 76 disposed in said bore. The opposite end of the cylinder 88 is closed by a plug 82 having a tapered externally threaded end portion threaded into a correspondingly tapered, internally threaded portion. Plug 82 is provided at its inner end with a bore 83 for slidable reception of the adjacent end portion of the pin 76 and the latter is urged downward-1y by a spring 84 operably disposed between the inner ends of the plug 82 and the adjacent side of the piston 78. Plug 82 has a head 85 having a recess 86 in the outer end for reception of a tool for actuating said plug and said head 85 is received entirely within the bore portion 87 which terminates in the tapered internally threaded portion in which the tapered portion of said plug 82 is screwed. Thelower end portion of the cylinder 80 is connected with the passage 33 by means of a lateral passage 88.

Generally, the upper end of the well is drilled substantially vertically. In order to reach the target area or oil bearing formation 28 which is spaced horizontally from the point of initiation of the well bore, the bore must be drilled on a curve toward said target area.

In using the present deflection tool described above for drilling a curved bore toward said target area, the arrangement shown in FIGS. 1 and 2 is used. Because of a difference in radial length of the recesses 68, the recess 68a being the shortest and the recess 68b being the longest, the axis of the tool will be offset when pump pressure is applied to the fluid in the tool and such pressure is transmitted through the lateral bore 45 to the groove 44 so that the fluid pressure may be applied between the outer surface of the adjacent part of the tool body 30 and the inner surface of the elastic, resilient body 48. As this fluid pressure is applied and the body 40 is caused to expand, the metallic runners or gripping elements 47 are forced outwardly .into engagement with the wall of the well bore so that there is substantially uniform engagement of the well bore by said gripping elements entirely about the circumference of the tool. The runners 47 prevent the body 40 from rotating in the well bore but permit longitudinal movement therein as drilling progresses. The collars 41 and 42 are also held against rotation by the elements 47 but the body 30 and end portions 31 and 32, which parts are shown as integrally formed, are adapt :d to rotate with the drilling string and effect rotation of the drill when the pin 76 is moved upwardly, as shown in the drawing, out of the recess 75 into which it has been disposed. Such movement of the pin 76 to the disengaging position is effected by fluid pressure transmitted from the passage 33, through the lateral bore 88 and into the lower end of the cylinder 80 below the piston 78.

It will be noted that in FIGS. 1 and 2 the deflection tool 20 is offset to the right while the deflection tool 24 is oifset to the left 180 relative to the tool 20, although other orientation may be used. This offsetting of the axis of the body portion 30 and end portions 31 and 32 is in respect to the axis of the resilient body 44 when the latter is expanded, such offsetting being best shown in FIG. 8.

The tools 20 and 24 are assembled on the surface in such a way that the individual deflecting forces are 180 opposed. In other words the collar 42 of the upper tool 24 is manually oriented in a given direction coinciding with the point of greatest movement of element 40 as shown at 6%, FIG. 10, and the pin 76 inserted to lock the collar in this position. The collar 42 of the lower tool 20 is similarly manually oriented 180 opposed to that of collar 42 of tool 24 and there locked. Conventional means may be used in determining the positions of these tools. For example, a register mark may be put on the part 42 showing the maximum throw.

The direction of the desired deflection having been determined by previously made underground surveys or other means, the bottom tool 20 is oriented on the surface of the rig floor in such a manner as to force defiection of the drilling bit in the desired direction. For example, in FIG. 8, the direction of deflection is to the right and the tool would be turned so that this di rection of deflection would correspond with the desired direction of deflection. After the lower tool 20 has been correctly oriented, the upper tool 24, previously assembled, is given a deflecting force 180 opposed to the lower tool, thereby compounding the effect of the two tools. In other words, if the lower tool 20 is given a deflecting force to the south, the upper tool 24 is given a deflecting force to the north. Once the lower tool is correctly oriented at the surface, the tools and drill string are run into the hole, the proper orientation being maintained by the conventional use of survey clamps as are commonly used when orienting a whip-stock.

When drilling operations are in progress with this equipment, the tools 2t? and 24 are secured in the above described relationship to each other on the collar 23 and when normal pump pressure prevails in the bore of the string and tools 20 and 24, the resilient body 40 is expanded to cause the elements 47 to grip the wall of the bore and to move the pin 76 to the released position,

as best shown in FIG. 6. The portions 30, 31 and 32 of the deflection tools are then free to rotate with the drill string, the portion 30 being carried by the bearings of the collars 41 and 42. When the deflection tools 20 and 24 are oriented as shown in FIGS. 1 and 2, the drill 16 is caused to drill on an arc, curving to the right as shown in FIG. 1.

When it is desired to add another length of pipe, rotation of the drill string is stopped and the pump pressure is released. Upon dropping of the pump pressure, the resilient body 40 contracts to the position shown in FIG. wherein the inner edges of the elements 47 en gage the body 30 so that the inner surface of the resilient body 48 is spaced somewhat from the outer surface of said body 3t? as best shown in FIG. 7. At the same time the pin 76 enters whichever recess 75 is aligned therewith. It is to be noted that because of the large number of recesses '75 and their close relationship to each other, there will be one of said recesses aligned with the 6 pin 76 in almost any rotational position of the part 32 with respect to the collar 42.

The string is then pulled up, the kelly removed, the length of pipe added, and the kelly again assembled on the top of the string. However, as the string is pulled up there must be no rotation of the kelly so that the string is kept from rotating to maintain the deflection tools 20 and 24 in their proper orientation or relationship with respect to the bore. The string and tools 20 and 24 must also be held against rotation when they are run back into the bore so that when they reach the lower end where drilling is to be continued, said tools 20 and 24 will be properly oriented in the bore for continued drilling toward the target.

Referring to FIG. 3, the upper tool is indicated at 24a. This tool is the same as tool 24 except that the body 3% and end portions 31 and 32 are not oifset aX- ially with respect to the axis of the resilient body 40 when the latter is expanded. Hence, this tool functions as a straight hole stabilizer above the drill collar. In order to have this coaxial arrangement of the body 30 and the resilient body 40 when the latter is expanded, the recesses for the end pins 48 of the elements 47 are of equal length, said recesses being indicated at 68c in FIG. 11. Also, this tool has the locking means eliminated.

Another arrangement is to use the stabilizer 24a at the top of the drill collars for straight hole drilling in com bination with only a regular drilling bit.

In FIG. 4 a reamer R is used as a stabilizer at the upper end of the collar 23 and this arrangement functions in substantially the same manner as the arrangement shown in FIG. 3. More particularly, in the arrangements shown in FIGS. 3 and 4 respectively, the tools 20 have the axial offsetting adjacent the drill hereinabove described so that the drill i6 is tilted slightly tothe right for drilling an arcuate bore curving to the right, but having a different radius from the bore drilled by the arrangement shown in FIGS. 1 and 2.

A further advantage of this arrangement is that it provides for sizing the hole as well as for maintaining the drift angle.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it is felt that it will be apparent that various changes may be made in the form, construct-ion and arrangement of the parts of the invention and the method of operation thereof without departing from the spirit and scope thereof or sacrificing all of its material advantages, the embodiments hereinhefore described being merely for purposes of illustration.

I claim:

1. Apparatus for controlling the direction and extent of deviation of a well bore by the rotary drilling method, comprising: a deflection tool having a body including a central portion and respective end portions of greater diameter than said central portion, there being means at each end of said body for connecting same to adjacent parts of drilling equipment, said body also having a longitudinaly extending bore therethrough; a pair of oppositely arranged collars spaced apart longitudinally on the central portion of the body and disposed adjacent the respective inner ends of the enlarged portions of said body; bearings for each of the collars operably disposed between the respective collars and the central portion of the body; thrust bearings for each of the collars for thrust load against the inner ends of the respective end portions of the body; sealing means between the outer ends of the respective collars and end portions of the body, said sealing means being positioned outwardly of the thrust bearings; sealing means between the collars and the central portion of the body, said sealing means being spaced inwardly of the first mentioned bearings of said collars; the facing ends of said collars being provided with corresponding radially extending annularly spaced recesses, the recesses of each of said collars being arranged with a short recess at one point and a relatively long recess at the diametrically opposite point, the intermediate re cesses at both sides of the short recess being progressively longer toward the long recess; a sleeve of resilient, elastic material on the central portion of the body between the inner ends of said collars; a plurality of elongated, relatively fiat gripping elements embedded in the resilient sleeve arranged radially and annularly spaced apart, the outer longitudinal edges of said gripping elements being exposed for gripping engagement with the Wall of a well bore when the resilient sleeve is expanded beyond the cylindrical plane of the outer surfaces of the end portions of the body and collars to hold against rotation but permitting longitudinal sliding movement, the outer edges of said elements being in substantially the said cylindrical plane when the resilient sleeve is contracted; end pins for each of the gripping elements, said end pins being received in respective radial recesses of said collars so that when said resilient sleeve is expanded the axis thereof will be offset with respect to the axis of said body, there being a lateral bore for the passage of pressure fluid from the longitudinal passage in said body to the interior of said sleeve, said gripping elements having recesses in the inner edges in the plane of the outer end of said lateral bore; one of said collars being a latching collar and being provided with a plurality of closely arranged, annularly spaced recesses and the adjacent enlarged portion of the deflection tool body being provided with a cylinder; a latching pin in said cylinder and mounted for longitudinal sliding movement into the last mentioned recesses of said collar; and a piston operably mounted in said cylinder and attached to said latching pin; and yielding means urging said piston and pin toward latching position; there being a lateral bore in said body connecting the longitudinally extending passage thereof with the end of the cylinder adjacent the latching collar for transmitting pressure fluid to the cylinder for urging the piston in a direction to move said latching pin out of a respective recess in the adjacent end of the adjacent collar.

2. Apparatus for controlling the direction and extent of deviation of a well bore by the rotary drilling method, including: a deflection tool having a body including a central portion and respective end portions of greater diameter than said central portion, said body having a longitudinally extending bore therethrough; a pair of oppositely arranged collars spaced apart longitudinally on the central portion of the body and rotatable thereon; sealing means between the respective collars and end portions of the body; sealing means between the collars and the central portion of the body; the facing ends of said collars being provided with corresponding radially extending annularly spaced recesses, the recesses of each of said collars being arranged with a short recess at one point and a relatively long recess at the diametrically opposite point, the intermediate recesses at both sides of the short recess being progressively longer toward the long recess; a sleeve of resilient material on the central portion of the body between the inner ends of said collars; a plurality of elongated, relatively flat gripping elements embedded in the resilient sleeve, arranged radially, and annularly spaced apart, the outer longitudinal edges of said gripping elements being exposed for gripping engagement with the wall of a well bore When the resilient sleeve is expanded beyond the cylindrical plane of the outer surfaces of the end portions of the body and collars; end pins for each of the gripping elements, said end pins being received in respective corresponding radial recesses of said collars so that when said resilent sleeve is expanded the axis thereof will be oifset with respect to the axis of said body, there being a lateral bore for the passage of pressure fluid from the longitudinal passage in said body to the interior side of said sleeve, said gripping elements having recesses in the inner edges; one of said collars being a latching collar and being provided with a plurality of closely arranged, annularly spaced latching recesses and the adjacent enlarged portion of the deflection tool body being provided with a cylinder; a latching pin in said cylinder mounted for longitudinal sliding movement into the latching recesses of said collar; a piston operably mounted in said cylinder and attached to said latching pin; and yielding means urging said piston and pin toward latching position; there being a lateral bore in said body connecting the longitudinally extending passage thereof with the end of the cylinder adjacent the latching collar for transmitting pressure fluid to the cylinder for urging the piston in a direction to move said latching pin out of a respective recess in the adjacent end of said latching collar.

3. A drill bit deflecting tool, including: a deflection tool having a body including a central portion and respective end portions of greater diameter than said central portion, said body having a longitudinally extending bore therethrough; a pair of oppositely arranged collars rotatably mounted on said central portion of the body and disposed adjacent the respective inner ends of the enlarged portions of said body; sealing means between the respective collars and adjacent portions of the body; the facing ends of said collars being provided with corresponding radially extending annularly spaced recesses, the recesses of each of said collars being arranged with a short recess at one point and a relatively long recess at the diametrically opposite point, the intermediate recesses at both sides of the short recess being progressively longer toward the long recess; a sleeve of resilient material on the central portion of the body between the inner ends of said collars; a plurality of elongated, relatively flat gripping elements embedded in the resilient sleeve and annularly spaced apart; end pins for each of the gripping elements, said end pins being received in corresponding radial recesses of said collars so that when said resilient sleeve is expanded the axis thereof will be offset with respect to the axis of said body, there being a lateral bore for the passage of pressure fluid from the longitudinal passage in said body to the interior of said sleeve; one of said collars being a latching collar and being provided with a plurality of closely arranged, annularly spaced latching recesses and the adjacent enlarged portion of the deflection tool body being provided with a cylinder; a longitudinally movable latching pin for movement into and out of respective latching recesses; a piston operably mounted in said cylinder and attached to said latching pin; and yielding means urging said piston and pin toward latching position; there being a lateral bore in said body connecting the longitudinally extending passage thereof with the cylinder for transmitting pressure fluid to the cylinder for urging the piston in a direction to move said latching pin out of latching position.

4. In an oifset drilling tool: a deflection tool having a body including a central portion and respective end portions of greater diameter than said central portion, said body also having a longitudinally extending bore there through; a pair of collars rotatably mounted on the central portion of the body, the facing ends of said collars being provided with corresponding radially extending, annularly spaced recesses of varying length, said recesses becoming progressively longer from one portion of the collar to a diametrically opposed portion; a sleeve of elastic material on the central portion of the body between the said collars; a plurality of annularly spaced, elongated, gripping elements embedded in the resilient sleeve, outer edge portions of said gripping elements being exposed for gripping engagement with the wall of a well bore when the resilient sleeve is expanded; end pins for each of the gripping elements, said end pins being received in radial recesses of corresponding length in the respective collars so that when said resilient sleeve is expanded the axis thereof will be offset with respect to the axis of said body, there being means for the transmission of pressure fluid from the longitudinal passage in said body to the interior of said sleeve; means for releasably latching at least one of the collars against rotation on said body, said means including a movable, pressure responsive latching element releasably engageable with one of said collars and movable out of latching position by the pressure of fluid in the tool; and yielding means urging said latching means into latching position.

5. In a directional drilling tool: a body having a central portion and enlarged end portions, said body having a longitudinally extending 'bore therethrough; an elastic sleeve rotatably mounted on bearing means on said central portion; means including said sleeve and central portion forming a substantially sealed space between the ends of said sleeve and said central portion; means in said body providing communication between said bore and said sealed space to supply fluid pressure from the bore to expand said sleeve; gripping elements carried by said sleeve for engagement with the wall of a well bore when said sleeve is expanded; means to limit the expansion of said sleeve a greater amount at one side than at a diametrically opposed side of the sleeve; pressure responsive releasable locking means for holding said sleeve and body against relative rotation, said locking means normally locking said sleeve and body means in said body providing communication between said bore and said locking means to supply fluid pressure to release said locking means. 6. In a deflection tool: a tubular body; an elastic sleeve rotatably mounted on bearing means on said body; means including said sleeve and said body forming a substantially sealed space between the ends of said sleeve and said body; means to supply fluid pressure to said sealed space to expand said sleeve; gripping elements carried by said sleeve for engagement with the wall of a well bore when said sleeve is expanded; means limiting expansion of said sleeve to limit the expansion of said sleeve a greater amount on one peripheral portion of said sleeve than on other peripheral portions; pressure responsive releasable locking means for holding said sleeve and body against relative rotation, said locking means normally locking said sleeve and body; and means to supply fluid pressure to said locking means to release it.

7. In a deflecting tool: a tubular body; an expandable sleeve rotatably mounted on bearing means on said body; means including said sleeve and said body forming a substantially sealed space between said sleeve and said body; means to supply fluid pressure to said sealed space to expand said sleeve; gripping elements carried by said sleeve for engagement with the Wall of a well bore when said sleeve is expanded; means to limit expansion of said sleeve; fluid pressure responsive releasable locking means for holding said sleeve and body against relative rotation; and means to supply fluid pressure to said locking means to release it.

8. In a tool for use in drilling operations; a cylindrical body; a fluid pressure expandable sleeve rotatably mounted on bearing means on said body; means including said sleeve and said body forming a substantially sealed space between said sleeve and said body; means to supply fluid pressure to said sealed space to expand said sleeve; gripping elements carried by said expandable sleeve for engagement wi h the wall of a well bore; and means limiting expansion of said sleeve.

9. Apparatus for controlling the direction and extent of deviation of a well bore by the rotary drilling method. comprising: a deflection tool including a cylindrical body; an expandable element rotatably mounted on bearing means on said body and expanded by a predetermined fluid pressure in said tool; means including said element and said body forming a substantially sealed space between said element and said body; means to supply fluid pressure to said sealed space to expand said element; gripping members carried by the said element for engagement with the wall of a well bore; means to limit the expansion of said sleeve a greater amount at one side than at a diametrically opposed side of the element; pressure responsive releasable locking means for holding said element and said body against relative rotation; means to supply fluid pressure to said locking means from said tool, said locking means being released by a predetermined fluid pressure so that said element and body may rotate relative to each other; means connecting a drill to said body at one end thereof; connecting means having one end connected to the other end of said body; and a deflection tool of the same construction as the first mentioned deflection tool and having one end connected to the other end of said connecting means, the second mentioned deflection tool being oriented so that the side of its expandable element having the greatest expansion will be oriented diametrically opposite the side of said element of the first mentioned deflection tool, having the greatest amount of expansion.

10. In combination with a rotary drill stem of a deflection tool including a cylindrical body connected at one end to said drill stem; an expandable element rotatably mounted on bearing means on said body; means including said element and said body forming a substantially sealed space between said element and said body; means to supply fluid pressure to said sealed space to expand said element; gripping members carried by the said element for engagement with the wall of a well bore; means limiting expansion of said element, said limiting means permitting greater expansion at one side than at a diametrically opposed side of the element; pressure responsive releasable locking means for holding said element and said body against relative rotation; means to supply fluid pressure to said locking means from said tool, said locking means being released by a predetermined fluid pressure so that said element and body may rotate relative to each other; a tubular collar having one end connected to the other end of said body, a deflection tool of the same construction as the first mentioned defiection tool and having one end connected to the other end of said collar, the second mentioned deflection tool being oriented so that the side of its expandable element having the greatest expansion will be oriented diametrically opposite with respect to the side of said element of the first mentioned deflection tool having the greatest amount of expansion; and a drill connected to the other end of the body of the second mentioned deflection tool.

11. Apparatus for controlling the direction and extent of deviation of a well bore of the rotary drilling method, comprising: a tubular member; a deflection tool at each end of said tubular member, each of said deflection tools including a spool shaped body having one end connected to said member and rotatable therewith, said body having a longitudinally extending bore therethrough; a pair of collars rotatably mounted on bearing means on the central portion of the body, the facing: ends of said collars being provided with corresponding radially extending, annularly spaced recesses of varying lengths, said recesses becoming progressively longer from one side to a diametrically opposed side of the collars; a sleeve of elastic material on the central portion of the body between said collars and associated to rotate therewith; means including said sleeve and said central portion forming a substantially sealed space between said sleeve and said central portion; means in said body providing communication between said bore and said sealed space to supply fluid pressure from the bore to expand the sleeve; a plurality of annularly spaced, elongated, gripping elements embedded in the resilient sleeve, the outer edges of said gripping elements being exposed for gripping engagement with the Wall of a well bore when the resilient sleeve is expanded; end pins for each of the gripping elements, said end pins being received in radial recesses of corresponding length in the respective collars so that when said resilient sleeve is expanded, the axis thereof will be offset with respect to the axis of said body; means for releasably latching at least one of the collars against rotation on said body, said means including a movable, pressure responsive latching element releasably engageable with one of said collars and movable out of latching position by the pressure of fluid in the tool; yielding means urging said latching means into latching position; and a drill attached to the end of a body of one of the deflection tools opposite the end of said body attached to said member, said deflection tools being so oriented that the offsetting of the respective sleeves are in opposite direction relative to the axis of the assembled apparatus.

12. In apparatus for controlling the direction and extent of deviation of a well bore by the rotary drilling method, comprising: a tubular member; a deflection tool at each end of said member, each of said tools having a body with one end connected to the adjacent end of said member for rotation therewith, said body having a longitudinally extending bore therethrough; a resilient sleeve rotatably mounted on bearing means on said body; means including said sleeve and said body forming a substantially sealed space between said sleeve and said body; means in said body providing communication between said bore and said sealed space to supply fluid from the bore to expand the sleeve; gripping element-s carried by said sleeve for engagement with the Wall of a well bore when the sleeve is expanded; means to limit the expansion of said sleeve a greater amount at one side than a diametrically opposed side of the sleeve; pressure responsive releasable locking means for holding said sleeve and body against relative rotation, said locking means being normally locked; means to supply fluid pressure to said locking means to release it; and a drill secured to the free end of the body of one of said deflection tools, the deflection tools being so oriented with respect to each other as to be oppositely offset with respect to the axis of the respective sleeves when the latter are expanded.

13. The combination with a rotary drill string of a tubular member; a deflection tool at each end of said tubular member, each of said deflection tools including a spool shaped body having one end connected to said member and rotatable therewith, said body having a longitudinally extending bore therethrough; a pair of collars rotatably mounted on the central portion of the body, the facing ends of said collars being provided with corresponding radially extending, annularly spaced recesses of varying lengths, said recesses becoming progressively longer from one side to the other; a sleeve of elastic material on the central portion of the body between said collars; a plurality of annularly spaced, elongated, gripping elements embedded in the resilient sleeve, the outer edges of said gripping elements being exposed for gripping engagement with the wall of a well bore when the resilient sleeve is expanded; end pins for each of the gripping elements, said end pins being received in radial recesses of corresponding length in the respective collars so that when said resilient sleeve is expanded, the axis thereof will be offset with respect to the axis of said body, there being means for the transmission of fluid pressure from the longitudinal passage in said body to the interior of said sleeve; means for releasably latching at least one of the collars against rotation on said body, said means including a movable, pressure responsive latching element releasably engageable with one of said collars and movable out of latching position by the pressure of fluid in the tool; yielding means urging said latching means into latching position; the body of one of said tools being connected to said drill string; and a drill attached to the end of the body of the other of said deflection tools opposite the end of said body attached to said member, said deflection tools being so oriented that the offsetting of the respective sleeves are in opposite direction relative to the axis of the assembled apparatus.

14. In combination with a rotary drilling string of a tubular member; a deflection tool at each end of said member, each of said tools having a body with one end 12 connected to the adjacent end of said member for rotation therewith, said body having a longitudinally extending bore therethrough; a resilient sleeve rotatably mounted on bearing means on said body; means including said sleeve and said body forming a substantially sealed space between said sleeve and said body; means in said body providing communication between said bore and said sealed space to supply fluid pressure from the bore to expand the sleeve; gripping elements carried by said sleeve for engagement with the wall of a well bore when the sleeve is expanded; means to limit the expansion of said sleeve a greater amount at one side than a diametrically opposed side of the sleeve; releasable locking means for holding said sleeve and body against relative rotation, said locking means normally locking said sleeve and body; means to supply fluid pressure to said locking means to release it; one of said deflection tools being operably connected to said string; and a drill operably secured to the other of said deflection tools, said sleeve on each deflection tool arranged to expand a greater amount on a diametrically opposite side with respect to each other so as to oppositely offset said deflection tools with respect to the axis of the respective sleeves when the latter are expanded.

15. The combination of a drill string with a tubular member; a deflection tool at each end of said tubular member, each of said deflection tools including a spool shaped body having one end connected to said member and rotatable therewith, said body having a longitudinally extending bore therethrough; a pair of collars rotatably mounted on the central portion of the body, the facing ends of said collars being provided with corresponding radially extending, annularly spaced recesses, the recesses of one of said deflection tools being of equal length while a the recesses of the other deflection tool being of varying length and being of progressively greater length from one side to the other; a sleeve of elastic material on the central portion of the body between said collars; a plurality of annularly spaced, elongated, gripping elements embedded in the resilient sleeve, the outer edges of said gripping elements being exposed for gripping engagement with the wall of a well bore when the elastic sleeve is expanded; end pins for each of the gripping elements, said end pins being received in said radial recesses in the respective collars, the sleeve and body of said one deflection tool being coaxial when the sleeve thereof is expanded while the axis of the body of the other deflection tool will be offset with respect to the axis of the sleeve when the latter is expanded, there being means for the transmission of fluid pressure from the longitudinal passage in each of said bodies to the interior of the respective sleeves; means for releasably latching at least one of the collars against rotation on the body of at least said other deflection tool, said means including a movable, pressure responsive latching element releasably engageable with one of said collars and movable out of latching position by the pressure of fluid in the tool; yielding means urging said latching means into latching position, said one deflection tool being operably connected to said string; and a drill attached to the end of a body of the other of the deflection tools opposite the end of said body attached to said member.

16. The combination of a drill string with a tubular member; a deflection tool at each end of said member, each of said tools having a body with one end connected to the adjacent end of said member for rotation therewith, said body having a longitudinally extending bore therethrough; a resilient sleeve rotatably mounted on bearing means on said body; means including said sleeve and said body forming a substantially sealed space between said sleeve and said body; means in said body providing communication between said bore and said sealed space to supply fluid pressure from the bore to expand the sleeve; gripping elements carried by said sleeve for engagement with the wall of a well bore when the sleeve is expanded; means to limit the expansion of one of said sleeves a greater amount at one side than a diametrically opposed side of the sleeve and limiting means for the other sleeve to provide uniform radial expansion in all directions; pressure responsive releasable locking means for holding the sleeve and body of said one deflection tool against relative rotation, said locking means being normally locked; means in said body to supply fluid pressure from said bore to said locking means to release it; and a drill secured to the free end of the body of said one deflection tool, the other deflection tool being connected to said drill string.

17. Directional drilling apparatus, comprising: a tubular member; a tool at each end of said tubular member, each of said tools including a spool shaped body having one end connected to said member and rotatable therewith, said body having a longitudinally extending bore therethrough; a pair of collars rotatably mounted on the central portion of the body, the facing ends of said collars being provided with corresponding radially extending, annularly spaced recesses, the recesses of one of said tools being of equal length while the recesses of the other tool being of varying length and being of progressively greater length from one side to the other; a sleeve of resilient material on the central portion of the body between said collars; a plurality of annularly spaced, elongated, gripping elements embedded in the resilient sleeve, the outer edges of said gripping elements being exposed for gripping engagement with the wall of a well bore when the resilient sleeve is expanded so that the sleeve is held against rotative movement relative to the well bore; end pins for each of the gripping elements, said end pins being received in said radial recesses in the respective collars, the sleeve and body of said one tool being coaxial when the sleeve thereof is expanded while the axis of the body of the other tool will be offset with respect to the axis of the sleeve when the latter is expanded, there being means for the transmission of fluid pressure from the longitudinal passage in each of said bodies to the interior of the respective sleeves; one of said tools having means for releasably latching at least one of the collars against rotation on said body, said means including a movable pressure responsive latching element releasably engageable with one of said collars and movable out of latching position by the pressure of fluid in the tool; and yielding means urging the latching means into latching position, said one tool being operably connected to said string.

18. In directional drilling apparatus: a tubular member; a deflection tool at one end of said member and a stabilizing tool at the other end thereof, each of said tools having a body with one end connected to the adjacent end of said member for rotation therewith, said body having a longitudinally extending bore therethrough; a resilient sleeve rotatably mounted on hearing means on said body; means including said sleeve and said body forming a substantially sealed space between said sleeve and said body; means in said body to provide communication between said bore and said sealed space to supply fluid pressure from the bore to expand the sleeve; gripping elements carried by said sleeve for engagement with the wall of a well bore when the sleeve is expanded; means to limit the expansion of the sleeve of the deflection tool a greater amount at one side than a diametrically opposed side of the sleeve and limiting means for the sleeve of the stabilizing tool to permit uniform radial expansion in all directions; pressure responsive releasable locking means for the deflection tool for locking the sleeve and body against relative rotation, said locking means being normally locked; and means in said body connecting said bore to said locking means to supply fluid pressure to release said locking means.

19. In a deflecting tool: a tubular body; an expandable sleeve rotatably mounted on bearing means on said body; means including said sleeve and said body forming a substantially sealed space between said sleeve and said body; means to supply fluid pressure to said sealed space to expand said sleeve; gripping elements carried by said sleeve and uniformly spaced circumferentially about said sleeve 'for engagement with the wall of a well bore in uniformly spaced relationship entirely about the circumference of said well bore when said sleeve is expanded; means to limit expansion of said sleeve; fluid pressure releasable locking means for holding said sleeve and body against relative rotation; and means in said body to supply fluid pressure to said locking means to release it.

20. In an offset drilling tool: a deflection tool having a body including a central portion and respective end portions of greater diameter than said central portion, said body having a longitudinally extending bore therethrough; a pair of bearing means rotatably mounted on the central portion of the body; a sleeve of elastic material on the central portion of the body between the said bearing means and associated for rotation therewith; means including said sleeve and said bearing means forming a closed fluid chamber between said bearing means and around and with said central portion; a plurality of spaced gripping elements in the elastic sleeve, outer edge portions of said gripping elements being exposed for gripping engagement with the wall of the well bore when the resilient sleeve is expanded; means connected to said bear-ing means to limit the expansion of said sleeve greater amounts at one portion of said sleeve than at other portions of said sleeve, there being means for transmission of fluid pressure from said bore in said body to the interior of said sleeve; means for releasably latching at least one of the bearing means against rotation on said body, said means including a movable, pressure responsive latching element releasably engageable with one of said bearing means and movable out of latching position by the fluid pressure in the tool; and means urging said latching means into latching position.

21. In a tool for use in drilling operations: a cylindrical body; a fluid pressure expandable sleeve rotatably mounted on hearing means on said body; means including said sleeve and said body forming a substantially sealed space between said sleeve and said body; means to supply fluid pressure to said sealed space to expand said sleeve; gripping elements integral with and expandable with said sleeve for engagement with the wall of the Well bore; and means limiting expansion of said sleeve.

References Cited in the file of this patent UNITED STATES PATENTS 1,549,168 Townsend Aug. 11, 1925 2,173,309 Monroe Sept. 19, 1939 2,194,331 Strom Mar. 19, 1940 2,295,803 OLeary Sept. 15, 1942 2,316,409 Downing Apr. 13, 1943 2,373,005 Baker Apr. 3, 1945 2,589,534 Buttolph Mar. 18, 1952 2,646,254 Johnston July 21, 1953 2,734,721 Zublin Feb. 14, 1956 2,745,635 Zublin May 15, 1956 2,783,028 Jamison Feb, 26, 1 957 

